A073821 Decimal expansion of number with continued fraction expansion 0, 2, 4, 6, ... (the even numbers).

4, 4, 6, 3, 8, 9, 9, 6, 5, 8, 9, 6, 5, 3, 4, 5, 0, 7, 0, 4, 7, 6, 8, 1, 7, 9, 5, 1, 9, 2, 6, 4, 2, 6, 6, 9, 7, 7, 6, 2, 5, 3, 1, 4, 7, 4, 0, 0, 3, 8, 7, 8, 2, 2, 8, 6, 1, 1, 9, 8, 9, 8, 6, 5, 4, 9, 5, 1, 4, 8, 9, 3, 1, 4, 4, 3, 6, 7, 5, 6, 2, 5, 6, 8, 6, 0, 7, 6, 8, 8, 0, 0, 6, 9, 9, 5, 1, 3, 6, 5, 8, 2, 2, 7

Offset: 0

Author

Rick L. Shepherd, Aug 12 2002

Keywords

• cons
• nonn

Examples

			0.44638996589653450704768179519...
		

Links

• Lucas A. Brown, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A005843 (even numbers), A052119 (continued fraction exp. is 0, 1, 2, 3, ...), A073747 (coth(1), continued fraction exp. is odd numbers).

Programs

Mathematica

RealDigits[FromContinuedFraction[2Range[0,200]],10,120][[1]] (* Harvey P. Dale, Oct 30 2011 *)

PARI

dec_exp(v)= {my(w=contfracpnqn(v)); w[1,1]/w[2,1]+0.0; }
dec_exp(vector(2000,i,2*(i-1)))

Formula

BesselI(1, 1)/BesselI(0, 1) (courtesy of the Inverse Symbolic Calculator).